I own a HP D7360 (<£100) consumer printer. It wasn't expensive and the colour prints are quite good. However I am having less than good results with B&W prints so I decided to nip down to Boots (chemist chain in UK) with an SD card to see whether their printer could do any better.

When I came to collect my pictures the assistant asked if they were "Professional Photographs" and was reluctant to hand over the prints. I got the impression she thought I had had them taken professionally and I was making extra copies thus infringing copyright!

How do I prove they are my images and what proof can I take next time to prevent such a situation.

First of all, even in the UK, the burden of proof lies with them, since they are illegally withholding your images.

But I suppose you can convince them by showing that you have the files. If you use the auto-comment feature of your camera to inject something to identify you in the EXIF file, you have established your case.

Furthermore, the EXIF data on your files should show the camera you used, further proving your point - if you choose to indulge in their paranoia and be polite about it.

I would suggest though, that if you choose to prove they are yours, call the police first and prove it to them instead.

When I came to collect my pictures the assistant asked if they were "Professional Photographs" and was reluctant to hand over the prints.

Did you ask why they needed to know? You should also have asked that if it was a requirement for you to notify them if the images were professional or not to use their service why you were not informed of this fact at the time you submitted them to be printed.

In some cases the questions asked by shop assistants are there to protect the company from being sued at a later date. For example when you buy a hydrocortisone cream they have to ask if you have used the product before and where (on your body) you will be using it. If you answer on your face they will not sell you the product. Another pharmaceutical restriction in the UK is on the sale of paracetamol or ibruprofen products, you are not allowed to buy more than two packs in any one transaction. However, you could go through the till fifty times generating separate transactions and be sold more than the restricted amount.

Just some examples of the law trying to save us from ourselves and failing with its stupidity.